Copolymers of vinylidene cyanide with vinylidene chloride



Patented Oct. 28, 1952 COPOLYMERS OF VINYIZIDENE CYANIDE WITH VINYLIDENECHLORIDE Vernon L. Felt, Akron, hio,,assi'gnor to TheBrF.

ration of New York Goodrich Company, NewYork, N...Y., a corpo- No Drawing. Application February' 14, 1 950, 'SeriaLNo. 144,1 9?

5 Claims. .1

'Ilnsinventionrelates. to the: preparation of novel copolymers of vinylidene. cyanide. with vinylidene chloride, which copolymers' are. extremely useful synthetic resins especially in the preparation of..fil'aments and films.

In US. Patent.2,476,2'70 to Alan E; Ardi's, and in copending applications. Serial, No.,63,fi34,,fiIed December 3, 1948, now U; S. Patent 2,502,412,

and Serial No. 79,712, filed March 4, l949',vnow U. S. Patent,2,514,38'7, novel methods for the preparationof monomeric vinylidene cyanide are disclosed. These methods involve, respectively, the pyrolysis at 400 C; to 750 C. of l-acetoxy-lpldicyano ethane, the pyrolysis of 1;1,3,3'-tetracyanopropane and the pyrolysis at 400 C11 to 800 C. of 4,4-dicyanocyclohexene, 4,4-di'carbamyl cyclohexene or 4-cyanor4-carbamyl' cyclohexene. In. another, copending application, Serial No. 11,336, filed February 26, 1948, methods for. the

preparation of useful homopolymers of vinyli'd'enei cyanide are disclosed.

Monomeric vinylidene cyanide is a clear liquid at room temperature and a crystalline solid at 0 C. It melts in the range. 01"610" C. to 917 6.,

depending on purity, with purestsamples melting at 9.0 C. to 9.7 0., and it boils at 40 C. at a reduced pressure of 5 mm. of mercury. It isquite unstable because of its extreme sensitivity to water, undergoing on contactwit'h water at room temperature an instantaneous homopolymerization reaction to give a solid, water-insoluble resin. When it is allowed to stand at room temperature in admixture with butadiene-1',3 it reacts there with to give solid 4,4-dicyanocyclohexane.

It has now been discovered that'when monorneric vinylidene cyanide of the above physical and chemical characteristics is copolymerized with vinyli'dene chloride, in the presenceof a free radical polymerization catalyst and a manner such. that "the. polymerization charge moi-78.5)

and a: is apolydigit, number, preferably from, to 15,000.

The fact that the copolymers thus obtained are essentially 1-:1 alternating copolymersis .determined by-analysis. of the copolymerfor nitrogen'and/or chlorine content which shows that the two monomers enter the polymer chain in essentially equimo-lar ratios regardless of the degree' of monomer to polymer conversion and of charging ratio provided the latter is within the range: of 5 to l5tmole per cent vinylidene cyanide. Furthersupporting evidence for this fact is found in the copolymerization equation of F. M. Lewis, G. Walling, eta-1., Journal of the American Chemica-l Society, '20, 1519 (1948).:

[Mil Concentration of unreacted monomer M1 lMc'lzconcen-tration of' unreacted monomer" M2 'TIZRatiO of the rate constants for the reaction ofan M1 type radical with M1 and M2 respectively rz:'Rati'o of the rate constants for the reaction of'an M2 type radical with M2 and Mr respectively Whenstheproduct x1, and m (the values of 171 and r2 being determined by solving the equation for n. and 172) is equivalent t zero, a 1:1 alternating copolymer isformed, that. is, a copolymer having the structure shown hereinabove. When M1 is vinyli. dene cyanide, andl lz is vinylidene chloride, it has been found that r1= l.093 and rz=0.0121; there fore, the product of m and m is 0.000592, which approaches zero so that the equation indicates that essentially alternating ccpolymers are formed.

The polymerization of this invention can, be

carried out'in a numberof ways. "sincevinylijdene cyanide and cin'yli'dene chloride are mutually soluble in one another, the polymerization may be carried out without" the use of a solvent or other liquid medium for the monomers, that is, simply by mixing together the two monomers and theperoxygen catalyst and allowing the mixture to stand, whereupon polymerization occurs to-form the desired copolymer as a white resinous powder of small particle size. thus formed may be separated from the polymerization mixtureby addingbenzene or other liquid aromatic hydrocarbon to dissolve the remaining monomersand then, filtering? off' the co- I polymer.

The copolymer A second and preferred method consists in first dissolving the vinylidene cyanide and the vinylidene chlorid in benzene or other aromatic solvent such as toluene, methyl toluene, trichloro benzene, or the like, preferably free from impurities which initiate the ionic polymerization of the vinylidene cyanide monomer, and in an amount such that the solvent comprises about 30 to 80% by weight of the total solution. A polymerization catalyst is included in this solution to effect the polymerization and the copolymer formed can be removed from the polymerization mixture simply by filtering.

Polymerization by the above methods occurs readily at room temperature. However, the polymerization may also be carried out at much lower temperatures, for example, as low as C., and at temperatures as high as 100 C., the use of temperatures in the range of 20 to 80 C. being preferred.

It is to be understood, of course, that regardless of the polymerization method utilized, the polymerization should be stopped before either of the monomers is entirely consumed, in order that pure copolymer will be obtained. Otherwise, when either of the monomers is completely used up, the product will contain straight polymer resulting from the polymerization of the remaining monomer. Accordingly, it is often desirable to add, continuously or intermittently, fresh quantities of one or both of the monomers, and also of catalyst and solvent if desired, to the polymerization mixture during the course of the polymerization, thus taking fullest advantage of the capacity of the equipment and in efiect operating a continuous or semi-continuous process.

The catalyst which is utilized in the polymer-'- ization processis preferably a peroxygen compound such as silver peroxide, the perborates, the percarbonateabenzoyl peroxide, caproyl peroxide, lauroyl peroxide, acetone peroxide, acetyl benzoyl peroxide, cumene hydroperoxide, o,o-dichlorobenzoyl peroxide, o,o'-dibromobenzoyl peroxide, caprylyl peroxide, pelargonyl peroxide, tertiary butyl hydroperoxide, and the like. In general, from 0.01 to 2.0% by weight (based on the total weight of the monomers charged) of the catalyst is utilized, although smaller or larger amounts may be utilized if desired. By regulating the amount of the catalyst it is possible to control very effectively and accurately the molecular weight of the copolymer. For instance, to obtain highest molecular weight copolymer, a small quantity of catalyst is used, while lower molecular weight copolymers are obtained by the use of larger amounts of catalyst.

The following examples illustrate the preparation of copolymers of vinylidene cyanide with vinylidene chloride in accordance with this invention, but are not to be construed as a limitation upon the scope thereof, for there are, of course, numerous possible variations and modifications. In the examples all parts are by weight.

EXAIVIPLES I TO III A series of copolymers are prepared by dissolving varying amounts of vinylidene cyanide and vinylidene chloride in 15.8 parts benzene, and adding to each of the mixtures 0.15% by weight (based on the total weight of the monomers) of o,o-dichlorobenzoyl peroxide as a polymerization catalyst. Polymerization is permitted to proceed with agitation for a period of 16 hours at room temperature after which the polymerization is stopped by cooling the mixtures to -20 C. The

solid resinous copolymer is recovered from the polymerization mixture by filtering. The charging ratios of the two monomers, mole per cent vinylidenecyanide in the charge and the mole per cent of vinylidene cyanide in the copolymer are recorded in Table I below:

EXAMPLES IV TO XI In the following examples vinylidene cyanide and vinylidene chloride are mass polymerized by mixing the monomers together and adding to each charge 0.15% by weight of o,o-dibromobenzoyl peroxide as the polymerization catalyst. After varying periods of time the polymerization is stopped by cooling the mixtures as in Examples I to III. Benzene is added to the polymerization mixtures to dissolve the remaining monomers and the solid resinous vinylidene cyanide: vinylidene chloride copolymer is recovered by filtering the resulting benzene slurry. In Table II below there are recorded the mole per cent vinylidene cyanide in each charge, the time during which the polymerization is permitted to continue, the per cent monomer to polymer conversion (based on total monomers charged) and the mole per cent vinylidene cyanide in the resulting copolymer (based on N and Cl analysis).

Table II Mole Mole Percent Polymeriza Percent Example Vmyhqene tion Time Perccnt vinylidene Cyanide (Hours) Conversion 0 ,amdein Charged Copolymei 6.14 16 2.0 46. 31 12.13 16 3. 5 49. O5 17. 98 16 3. 6 50. 23. 70 1 16 to 24 2 4. 0 to 18.0 52. 39 29. 29 6.1 51. 94 34. 75 16 to 24 7.0 to 17.3 51.46 45. 31 l 16 to 24 1 7.0 to 17.5 51. 55 55. 11 l 16 to 24 2 8.0 to 18. 5 51.

Several runs carried outat polymerization times Within this range, utilizing the same charging ratios.

3 Several runs carried out using the same charging ratios polymerized to diilerent conversions within this range.

It will be seen from the above examples that an essentially 1:1 alternating copolymer is obtained when the polymerization charge contains from 5 to 90 mole per cent of vinylidene cyanide. When the polymerization is carried out according to the other methods described hereinabove, or at temperatures as high as 50 C. or higher, or utilizing other of the peroxygen catalyst herein disclosed, the essentially 1:1 alternating copolymer is again readily obtained.

The copolymers of vinylidene cyanide with vinylidene chloride prepared according to this invention are useful in the preparation of solutions from which can be spun fibers and filaments of any desired size which possess many advantageous properties including extremely high strength, low elongation, outstanding resistance to weathering and excellent resistance to the action of chemicals. Thus, for instance, when the copolymers obtained in the above examples are dissolved in dimethyl iormamide, viscous solutions result, and such solutions are suitable for being spun through a spinneret into a spinning bath to give excellent filaments. The physical properties of these filaments can be improved by a hot-stretching process, whereby the filament is stretched in a hot zone in a series of steps, a process disclosed in a copending application of Harry Gilbert, Serial No. 113,018, filed August 29, 1949. In addition to the use of dimethyl formamide, other solvents for the copolymers may also advantageously be used, and the copolymer solutions are also useful for the casting of valuable films having good flexibility properties. Also, since the copolymers of this invention soften when heated to high temperatures, they may be melt spun and may be used in the preparation of molded objects. They possess softening points of the order of 220 to 250 C.

Although specific examples of the invention have been herein described, it is not intended to limit the invention solely thereto, but to include all of the variations and modifications falling within the spirit and scope of the appended claims.

I claim:

1. A copolymer of vinylidene cyanide and vinylidene cyanide and vinylidene chloride, said copolymer possessing essentially the structure wherein each M1 represents a vinylidene cyanide unit, each M2 represents a unit of said vinylidene chloride and :c is a polydigit number, in which copolymer the vinylidene cyanide units are derived from monomeric vinylidene cyanide which is a liquid at room temperature and a crystalline solid at C., having a melting point, when in purest form, of substantially 9.0 C. to 917 C., and being characterizable chemically by the ability to undergo on contact with water at room temperature an instantaneous homopolymerization reaction to give a solid, water-insoluble resin.

2. The method which comprises preparing a mixture containing monomeric vinylidene cyanide, monomeric vinylidene chloride and a peroxygen catalyst, the monomeric vinylidene cyanide being present in said mixture in an amount from 5 to 90 mole per cent based on the total monomer weight and being a liquid at room temperature and a crystalline solid at 0 C. having a melting point, when in purest form, of substantially 9.0 C. to 9.'7 C., and being characterizable chemically by the ability to undergo on contact with water at room temperature an instantaneous homopolymerization reaction to give a solid, water-insoluble resin, and maintaining the said mixture at a temperature of 20 C. to C. for a time sufiicient to effect copolymerization of the said vinylidene cyanide and vinylidene chloride and formation of a solid, resinous copolymer possessing essentially the structure wherein each M1 is a vinylidene cyanide unit, each M2 is a unit of said vinylidene chloride and as is a polydigit number.

3. The method which comprises preparing a solution containing monomeric vinylidene cyanide, monomeric vinylidene chloride, a peroxygen catalyst and a solvent selected from the class consisting of aromatic hydrocarbons and chlorinated aromatic hydrocarbons, the monomeric vinylidene cyanide being present in said solution in an amount from 5 to mole per cent based on the total monomer weight and being a liquid at room temperature and a crystalline solid at 0 C., having a melting point, when in purest form, of substantially 9.0 C. to 9.7" C., and being characterizable chemically by the ability to undergo on contact with water at room temperature an instantaneous homopolymerization reaction to give a solid, water-insoluble resin, and maintaining the said solution at a temperature of 20 C. to 80 C. for a time sufiicient to effect copolymerization of the said vinylidene cyanide and vinylidene chloride and precipitation of a solid, resinous copolymer from the solution, said copolymer possessing essentially the structure wherein each M1 is a vinylidene cyanide unit, each M2 is a unit of vinylidene chloride and x is a polydigit number.

4. The method of claim 3 in which the solvent comprises from 30% to 80% by weight of the solution and the peroxide catalyst is present in an amount from 0.01% to 2% by weight based on the total amount of monomeric vinylidene cyanide and monomeric vinylidene chloride.

5. The method of claim 3 further characterized in that the solvent is benzene and the peroxygen catalyst is o,o-dichlorobenzoyl peroxide.

VERNON L. FOLT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,455,653 Bralley Dec. 7, 1948 2,466,395 Dickey Apr. 5, 1949 

1. A COPOLYMER OF VINYLIDENE CYANIDE AND VINYLIDENE CYANIDE AND VINYLIDENE CHLORIDE, SAID COPOLYMER POSSESSING ESSENTIALLY THE STRUCTURE 